Atoms! Ya can’t trust them, they make up everything!

Matter Matter is anything that has mass and takes up space! We have many different types of matter: pure substances, and mixtures. Law of Conservation of Matter – Matter can be neither created nor destroyed, merely transformed.

Most basic chemical - Atoms Atoms are the smallest particles to have chemical properties. There are smaller particles, but they do not have chemical properties Atoms are made up of smaller particles called protons, neutrons, and electrons Different numbers of protons, neutrons and electrons determine an atom’s properties

Subatomic Particles Protons, Neutrons, and Electrons are called subatomic particles because they are what make up atoms. “Sub” meaning “within” or “beneath” the atom

Subatomic particles Protons are: POSITIVELY CHARGED like the south end of a magnet BIG and GIVE the atom MASS They do not move within the atom They give the element its identity Neutrons are: NEUTRAL/HAVE NO CHARGE BIG and GIVE the atom MASS They do not move within the atom Stabilize the protons Make up an atom’s nucleus

Subatomic particles (continued) Electrons are: NEGATIVELY CHARGED like the north end of the magnet SMALL and DO NOT give the atom MASS Move rapidly around the nucleus Their movement is responsible for chemical reactions Make up an atom’s electron cloud

Each atom has a nucleus made up of protons and neutrons Each element has a unique number of protons

Properties of an atom Atomic number: the number of protons; it tells us which element the atom is for. Mass number: the number of protons plus the number of neutrons; how much the atom weighs. Charge: the positive charges plus the negative charges; if it is neutral, the number of protons is equal to the number of electrons

Atoms and Subatomic Particles If an atom is neutral, the # of electrons equals the atomic number IF NEUTRAL: # electrons = # protons If you are given an atom’s atomic mass #, you can calculate the number of neutrons by subtracting the number of protons from this atomic mass # Mass # - Atomic # = # of Neutrons If you have the # of neutrons you can add them to the # of protons to discover the mass number Atomic # + # of Neutrons = Mass #

Pure substances - Atoms Pure substances contain only one type of particle (a unit of chemistry), whether they are atoms or compounds There are different types of atoms called elements. Each element has a different number of protons Each element has different characteristics from one another, especially associated with their class

Ions/ Isotopes Ions – atoms that have charge due to losing/gaining electron(s). Example: Na – electron = Na +1 Example: F + electron = Na -1 *Isotopes – atoms of the same element that have a different # of neutrons & mass. 12 C 6 = 6 protons & 6 neutrons vs. 13 C 6 = 6 protons & 7 neutrons

Periodic table Our periodic table directly tells us: The atomic number (how many protons) The average atomic mass (an average of all the atoms of that element) The symbol of the element The name of the element

Periodic Table Our periodic table tells us whether an element is a : a metal (to the left of the staircase) metalloid (touching the stair case) non-metal (to the right of the stair case) noble gas (the last column on the right) **(These are classes of elements)

Metals Metalloids Non-metals Noble gases

Pure Substances - Compounds When elements chemically bond together, they form a NEW UNIT of matter called a compound Compounds have different properties from the elements that make them up Example, both hydrogen and oxygen support flame, yet, H 2 O (Water) puts out flames!

Mixtures – a substance that contains 2 or more units of chemistry Homogeneous –mixtures that are evenly distributed, even on the atomic/molecular level Heterogeneous – mixtures that are not evenly distributed 100%, especially not on the atomic/molecular level.